• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6464-6471
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• 2014

The UV curing method is a popular process for lens molding on a unit wafer. This process, however, has several drawbacks including wafer adhesion during the ejection process after curing, errors in lens shape and wafer warpage due to material shrinkage during the curing process, and lens centering errors on both sides of a wafer. Among these, the lens shape error and warpage are influenced directly by the UV curing process due to factors including the UV radiation uniformity, the degree of cure according to UV intensity, and the shrinkage characteristics of the material. Therefore, a theory is needed not only to understand the change in the material characteristics, such as the shrinkage rate due to the curing reaction, but also to establish a model. In addition, an analysis system is needed to realize the model. This study proposes a new analysis method for the wafer lens molding process by Comsol modeling. This method was verified by comparing the results with those of the actual process.

• Journal of Korean Library and Information Science Society
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• v.48 no.4
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• pp.21-47
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• 2017

This study aims to analyze features of topics about AI(Artificial Intelligence) which is gaining a massive attention these days. Newspaper articles published from 2016 to June, 2017 were selected to analyze key subjects. The reason why the period was selected is people started to get attention on AI since 2016 as AlphaGo came out and gave a shock. The number of coded main message was 1,210 in 525 newspaper articles in total. The messages were categorized as three subject categories: the seven major categories, 62 middle categories. and minor categories. The seven major categories contains issues such as AI research, AI application, AI business, AI era, AI argument, AlphaGo, and other topics. The first features of issues about AI found in the major subject categories is that they are various and complicate. Second, it is important that social and policy-level issues related AI, such as job losses, misuse, and error should be dealt with to utilize AI safely. Last, issues related the role of human and revolution of education system in the AI era were shown as subjects which are important but hard to discuss.

• Journal of Korea Multimedia Society
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• v.17 no.7
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• pp.818-828
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• 2014

After emerging of Microsoft Kinect, the interest in three-dimensional (3D) depth image was significantly increased. Depth image data of an object can be converted to 3D coordinates by simple arithmetic calculation and then can be reconstructed as a 3D model on computer. However, because the surface coordinates can be acquired only from the front area facing Kinect, total solid which has a closed surface cannot be reconstructed. In this paper, 3D registration method for multiple Kinects was suggested, in which surface information from each Kinect was simultaneously collected and registered in real time to build 3D total solid. To unify relative coordinate system used by each Kinect, 3D perspective transform was adopted. Also, to detect control points which are necessary to generate transformation matrix, 3D randomized Hough transform was used. Once transform matrices were generated, real time 3D reconstruction of various objects was possible. To verify the usefulness of suggested method, human arms were 3D reconstructed and the volumes of them were measured by using four Kinects. This volume measuring system was developed to monitor the level of lymphedema of patients after cancer treatment and the measurement difference with medical CT was lower than 5%, expected CT reconstruction error.

• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.251-258
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• 2003

A support vector machine (SVM) is supposed to provide a good generalization performance, but the actual performance of a actually implemented SVM is often far from the theoretically expected level. This is largely because the implementation is based on an approximated algorithm, due to the high complexity of time and space. To improve this limitation, we propose ensemble of SVMs by using Bagging (bootstrap aggregating) and Boosting. By a Bagging stage each individual SVM is trained independently using randomly chosen training samples via a bootstrap technique. By a Boosting stage an individual SVM is trained by choosing training samples according to their probability distribution. The probability distribution is updated by the error of independent classifiers, and the process is iterated. After the training stage, they are aggregated to make a collective decision in several ways, such ai majority voting, the LSE(least squares estimation) -based weighting, and double layer hierarchical combining. The simulation results for IRIS data classification, the hand-written digit recognition and Face detection show that the proposed SVM ensembles greatly outperforms a single SVM in terms of classification accuracy.

• Journal of KIISE:Information Networking
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• v.27 no.1
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• pp.88-97
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• 2000

Applied with multicast transmission techniques in mobile computing environments, a mobile host will experience join and graft delay, happened when a host wants to join a multicast group in the fixed network, if there are no same multicast group member in the new cell the mobile host enters. Due to low bandwidth and higher error rate, there happens many additional traffic. In this paper, we propose a pre-join technique which new mobile support station joins the multicast group in advance based on signal strength hint in the current cell. We use the multiple level acknowledgement strategy that executes acknowledgment separately between the fixed part and the wireless transmission path. Using our strategy, it is an efficient technique in case there are more cells that has no multicast group members and less mobile host movements.

• Nutrition Research and Practice
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• v.12 no.4
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• pp.283-290
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• 2018

BACKGROUND/OBJECTIVES: Indirect calorimetry is the gold-standard method for the measurement of resting energy expenditure. However, this method is time consuming, expensive, and requires highly trained personnel. To overcome these limitations, various predictive equations have been developed. The objective of this study was to assess the validity of predictive equations for resting energy expenditure (REE) in Korean non-obese adults. SUBJECTS/METHODS: The present study involved 109 participants (54 men and 55 women) aged between 20 and 64 years. The REE was measured by indirect calorimetry. Nineteen REE equations were evaluated for validity, by comparing predicted and measured REE results. Predictive equation accuracy was assessed by determining percent bias, root mean squared prediction error (RMSE), and percentage of accurate predictions. RESULTS: The measured REE was significantly higher in men than in women (P < 0.001), but the difference was not significant after adjusting for body weight (P > 0.05). The equation developed in this study had an accuracy rate of 71%, a bias of 0%, and an RMSE of 155 kcal/day. Among published equations, the $FAO_{weight}$ equation gave the highest accuracy rate (70%), along with a bias of -4.4% and an RMSE of 184 kcal/day. CONCLUSIONS: The newly developed equation provided the best accuracy in predicting REE for Korean non-obese adults. Among the previously published equations, the $FAO_{weight}$ equation showed the highest overall accuracy. Regardless, at an individual level, the equations could lead to inaccuracies in a considerable number of subjects.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.1
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• pp.30-40
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• 2011

Numerical simulations were carried out to investigate the impact of SST spatial distribution on the result of air quality modeling. Eulerian photochemical dispersion model CAMx (Comprehensive Air quality Model with eXtensions, version 4.50) was applied in this study and meteorological fields were prepared by RAMS (Regional Atmospheric Modeling System). Three different meteorological fields, due to different SST spatial distributions were used for air quality modeling to assess the sensitivity of CAMx modeling to the different meteorological input data. The horizontal distributions of surface ozone concentrations were analyzed and compared. In each case, the simulated ozone concentrations were different due to the discrepancies of horizontal SST distributions. The discrepancies of land-sea breeze velocity caused the difference of daytime and nighttime ozone concentrations. The result of statistic analysis also showed differences for each case. Case NG, which used meteorological fields with high resolution SST data was most successfully estimated correlation coefficient, root mean squared error and index of agreement value for ground level ozone concentration. The prediction accuracy was also improved clearly for case NG. In conclusion, the results suggest that SST spatial distribution plays an important role in the results of air quality modeling on high ozone episode at coastal region.

• Journal of Astronomy and Space Sciences
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• v.18 no.2
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• pp.163-173
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• 2001

In this paper, space radiation environment and single event effect(SEE) have been analyzed for the KOMPSAT-2 operational orbit. As spacecraft external and internal space environment, trapped proton, SEP(solar energetic particle) and GCR(galactic cosmic ray) high energy Protons and heavy ions spectrums are analyzed. Finally, SEU and SEL rate prediction has been performed for the Intel 80386 microprocessor CPU that is planned to be used in the KOMPSAT-2. As the estimation results, under nominal operational condition, it is predicted that trapped proton and high energetic proton induced SBU effect will not occur. But, it is predicted that heavy ion induced SEU can occur several times during KOMPSAT-2 3-year mission operation. KOMPSAT-2 has been implementing system level design to mitigate SEU occurrence using processor CPU error detection function of the on-board flight software.

• Journal of Navigation and Port Research
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• v.36 no.10
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• pp.795-801
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• 2012

This paper describes theoretical approach methodology for the Probability based risk Evaluation Techniques (PET) to monitor the risk levels of small-sized sea floater as like a yacht pier. The risk decision-making process by risk criteria with five-step scales is the core concepts of PET. These five-step scales are calculated from cumulative probability distribution of response functions for the sea floater motions using closed-form expressions. In addition, The risk decision-making process of PET with the risk criteria is proposed in this work. To verify the usability of PET, simulation experiments are carried out using mimic signals with the electrical specifications of ADIS16405 sensor that is to be use as measurement tool for the floater motions. As results from experiments, the risk evaluation error by PET shows 0.38 levels in maximum 5.0 levels. These results clearly shown that the proposed PET can be use as the monitoring techniques.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.390-395
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• 2020

For some processes with saturations, economical operating points are on the saturation edges. Traditional feedback controllers cannot be used to regulate such processes on the saturation edges because there are abrupt dynamics changes and no feedback information at saturations. Optimization-based methods such as the model predictive control can treat this control problem without difficulty when the saturation levels and dynamics are known and not varying. Otherwise, an adaptation scheme to track the saturation levels and dynamics should be included. Here, for very simple methods to treat this control problem, two control methods based on the recent slope seeking method and the relay feedback method are proposed. Their performances are evaluated with simulations applying them to a second order liquid level system with saturation. Simulations show that these proposed control methods can find and maintain operating point of the saturation edge under 5% relative error.